The present invention relates generally to equipment for use in limited oxygen environments or the like and, more particularly, to a device for operating inflation and deflation valves of an air chamber of a scuba diver""s balancing jacket.
The use of balancing jackets to enable the scuba diver to assume a vertical position is well known in the sector of underwater activities. These jackets contain an air chamber that can be inflated to facilitate upward moves of the diver and deflated to accelerate his descent. The jacket is inflated by using the air contained in the cylinders forming part of the diver""s equipment, the diver opening an appropriate valve for this purpose. The air release from the jacket, on the other hand, is brought about by the external pressure when the diver opens one or more discharge valves.
Traditional solutions of this problem see the jacket provided with a corrugated conduit, generally a tube of considerable flexibility, starting from the upper part of the jacket and provided at its free end with means for operating both the inflation and the deflation valves. The tube has a length of several tens of centimeters and is left to fluctuate around the diver. Whenever the diver wishes to change his vertical position, he can get hold of the end of the tube and operate the particular control that will bring about the desired volume change of the air chamber of his jacket.
It should here be borne in mind that a deflation of the jacket will diminish the diver""s buoyancy and will therefore cause him to descend to a greater depth. As a general rule, this descent, which takes place rather slowly, does not imply any particular risks for the diver and the discharge valve can therefore be operated with relative freedom. The inflation of the jacket""s air chamber, on the other hand, calls for greater attention, since an excessive air inflow and a corresponding increase of the diver""s buoyancy will cause therefore a rapid upward movement with dangerous consequences for the diver.
Given this situation, the appropriate instruction manuals tell the diver that, on getting hold of the corrugated conduit of the conventional type, he should pull it upwards when he wishes to rise towards the surface and pull it downwards when he wishes to descend further: in this way he will reduce the possibility of operating the wrong valve and the dangerous consequences that could stem therefrom, especially in emergency conditions.
According to the conventional solution, inflation of the jacket is obtained by operating a push-button situated at the end of the corrugated conduit, while deflation is produced by means of one or more of the following procedures: pulling the conduit away from the body, pressing of a push-button, pulling a small cord that projects from the jacket. In each case, however, the diver must first find the operating means and this obliges him to make a more or less extensive movement or displacement of his arm.
According to a previous patent of the same applicant, the air chamber of the jacket is provided with a multiplicity of discharge valves and when the jacket has to be deflated, these can be opened simultaneously thanks to mechanical connection means that can be operated in the vicinity of the discharge valves, generally situated at the top side and bottom side of the jacket. In this way the diver can operate all these valves at the same time, choosing the position he finds most comfortable according to the position of his hand.
The object of the present invention is to provide a device for operating the inflation and deflation valves positioned in such a way that, no matter what may be the position of the diver""s hand, it will be instinctive for him to place it onto the proposed device.
Another aim of the present invention is to provide a device of the aforementioned type provided with means that the diver can operate to control the valves of his jacket and therefore comprising means that will transmit the operating command to the various valves, said transmission means being realized in such a manner as to assure the greatest possible constructional simplicity and therefore also the greatest possible certainty of proper operation.
According to the invention, the inflation and deflation valve operating device of the jacket is constituted by a handgrip that projects from the bottom portion of the jacket at a lateral/front position thereon. It can therefore be reached by just a slight bending of the diver""s arm to bring his hand close to his hip, which is also the position where his jacket terminates.
Furthermore, using underwater goggles with downward-pointing lenses as envisaged by a previous invention of the same applicant, said handgrip will also be perfectly visible for the diver.
Said handgrip is of such size as to completely fill the diver""s hand, so that even when he is wearing gloves, it will be easy for him to grip it and operate the means for controlling the inflation or deflation of the jacket without being left in doubt as to whether or not he has operated them, said means being realized in such a manner as to make the diver perform the correct operation on each occasion. The position of the handgrip, which projects from a small sleeve attached to the jacket, is such that, whenever the diver gets hold of it, his forearm will be bent slightly forward and downward. This relative position helps the diver to make the correct choice between the inflation and deflation controls of the jacket.
According to a preferred embodiment of the invention, the upper surface of the handgrip is provided with a sliding push-button or cursor that can be pushed forward and then slightly downwards by means of a movement of the thumb. When the diver uses his thumb to push said cursor forward and then downward, be it even slightly, he causes the discharge valve or valves of his jacket to open and this, in turn, will diminish his buoyancy and thus cause him to descend further into the water.
For the purpose of opening the inflation valves of the jacket, the handgrip is provided with a push-button on the side of its internal face that can be operated with the diver""s index finger or, better, his middle finger. This operation, though just as easy as the previous one, requires the diver to consciously search for the inflation button and therefore avoids untimely operation that could have dangerous consequences.
Both the deflation cursor and the lateral inflation button are provided with elastic means to bring them back into their original positions.
According to another particularly preferred feature of the invention, the handgrip comprises means of the mechanical type to transmit the operating command to the deflation valve, said sliding push-button being connected to the mobile shutter of the deflation valve by means of a kinematic motion mechanism consisting of a piston and a control cable. The means for transmitting the operating command to the inflation valve, on the other hand, are of the pneumatic type and take the form of a pneumatic circuit that is activated by a pilot valve operated by the aforesaid lateral push-button.